purify vs improve

purify and improve both are verbs.

Word	Noun	Adjective	Verb	Adverb
purify	No	No	Yes	No
improve	No	No	Yes	No

As verbs, improve is a hypernym of purify; that is, improve is a word with a broader meaning than purify:

purify: remove impurities from, increase the concentration of, and separate through the process of distillation
improve: to make better

Other hypernyms of purify include ameliorate, amend, better, meliorate.

purify (verb)	improve (verb)
remove impurities from, increase the concentration of, and separate through the process of distillation	get better
make pure or free from sin or guilt	to make better
become clean or pure or free of guilt and sin